package com.lzy.util;

public class IpConverter {
	//将127.0.0.1形式的IP地址转换成十进制整数，这里没有进行任何错误处理
    public static long ipToLong(String strIp) {
        long[] ip = new long[4];
        //先找到IP地址字符串中.的位置
        int position1 = strIp.indexOf(".");
        int position2 = strIp.indexOf(".", position1 + 1);
        int position3 = strIp.indexOf(".", position2 + 1);
        //将每个.之间的字符串转换成整型
        ip[3] = Long.parseLong(strIp.substring(0, position1));
        ip[2] = Long.parseLong(strIp.substring(position1+1, position2));
        ip[1] = Long.parseLong(strIp.substring(position2+1, position3));
        ip[0] = Long.parseLong(strIp.substring(position3+1));
        return (ip[0] << 24) + (ip[1] << 16) + (ip[2] <<  8 ) + ip[3];
    }
   
    //将十进制整数形式转换成127.0.0.1形式的ip地址
    public static String longToIP(long longIp) {
        StringBuffer sb = new StringBuffer("");
        sb.append(String.valueOf((longIp & 0x000000FF)));
        sb.append(".");
        sb.append(String.valueOf((longIp & 0x0000FFFF) >>>  8 ));
        sb.append(".");
        sb.append(String.valueOf((longIp & 0x00FFFFFF) >>> 16));
        sb.append(".");
        sb.append(String.valueOf((longIp >>> 24)));
        return sb.toString();
    }
    
    public static void main(String[] args) {
    	System.out.println(IpConverter.longToIP(3390061751L));
    	System.out.println(IpConverter.ipToLong("183.60.16.202"));
	}
}
